Re: [PATCH net v2] bnxt_en: Fix TX timeout during netpoll.

From: Michael Chan <michael.chan@broadcom.com>
Date: Wed, 26 Sep 2018 00:41:04 -0400

The current netpoll implementation in the bnxt_en driver has problems
that may miss TX completion events.  bnxt_poll_work() in effect is
only handling at most 1 TX packet before exiting.  In addition,
there may be in flight TX completions that ->poll() may miss even
after we fix bnxt_poll_work() to handle all visible TX completions.
netpoll may not call ->poll() again and HW may not generate IRQ
because the driver does not ARM the IRQ when the budget (0 for netpoll)
is reached.

We fix it by handling all TX completions and to always ARM the IRQ
when we exit ->poll() with 0 budget.

Also, the logic to ACK the completion ring in case it is almost filled
with TX completions need to be adjusted to take care of the 0 budget
case, as discussed with Eric Dumazet [off-list ref]

Reported-by: Song Liu <redacted>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>

Applied and queued up for -stable, thanks Michael.